Xs1b front upgrade winter project

angus67

angus67

Welder's penetrate deeper!!
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Trying to get my ducks in a row here.
I have a 1971 xs1-b, in very good condition.
The front end has never been apart, so, the fork oil is likely degraded 30wt, and the grease in the head bearings is likely peanut butter.
Here's the plan--
Clean out forks, and install all balls tapered head bearings. I've read a lot about the tapered bearing upgrade, and have it on my 1980 chop. I assume it's the same kit. The one in my chop is the one from mikexs, and hope the all balls kit will install the same.
Am I safe to assume all heads thru the xs run are the same?
I've read a lot about making slots to make the new races removable in the future and plan to do so.
As for the forks, other than a kerosene clean out, and 15wt fork oil, how can I firm up this front end? The whole bike is a bit bouncy, the back shocks are mush as well, but want the stock look. Replacements seam too cheap to be any good. Just keep an eye on eBay for a good set and hope the seller knows a good shock from bad?
I know I'm limited with these early forks, and have looked at Minton mods, I don't expect to make a canyon carver out of this bike, but want to feel a significant improvement in ride and handleing.
Open to any and all suggestions.
The entire front end will be off, and would like to get it all in one shot.
 
Found hughs tutorial on early fork dismantal. I'm not looking to lower it, but pictures build confidence. Looks easier than the later forks. Minton mods was no help. Maybe I didn't see it, but looks like it's only for later forks.
 
Find yourself a later type xs1 fender, it's in the yamaha parts list
This one has a kind of " bridge" between the fork legs, instead of the small mountings. My XS1 has this construction and I have been able to compare. It is a hudge improvement.
 
Fresh oil will probably help a lot, a little more than the stock amount probably will too. Just don't go over board. Too much oil can blow the seals. A general rule of thumb for oil amounts is 6" from the tops of the tubes, measured with the springs out and forks fully compressed. I would add the stock amount of oil and take that measurement, then tailor the level from there. Raising it an inch or so is usually good. On the later forks, a half ounce more of oil raises the level about an inch.

Yes, the Minton Mods were done on the later forks. If you find the same damper rod oil holes on yours, I don't see why they wouldn't work on this fork. If it was me, I'd acquire a second set of damper rods to mod in case it didn't work. Then you could put the old originals back.
 
Can't help you much with customizing and mods on these early forks.

But, I do like my Frappuccino.

XS1B-ForkOil.jpg

Tried 10wt and 15wt oils, too soft for the rocky roads out here.
Happy with budget 20w-50.
Cut and fitted top spring spacers from plumbing pipe to get about 1-1/2" sag into the fork bottoms, with me sitting on it.
 
I have 15wt in my 1980 chop with 35mm forks, and like it. I have a 1972 xl250 for the rough stuff, so looks like best avenue for the 34mm forks is just a good clean out and new seals. Are seals from Moines adequate , or should I buy elsewhere?
 
One would hope such a religious zealot would be honest though .....
 
You could find a couple of old Guard stays, up to 76 and make a fork brace and use it in conjunction with what you are running. Like this but keep the guard you have on it
 

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I'm keeping my drum, so thanks anyway, skull .
Like said, not looking to turn this bike into a canyon carver, so, not really looking for a radical change in looks just to stiffen up the forks(twist). I think I will just rebid the forks with new seals. Will one oz more of fork oil be a good way to go, 5t?
I'm keeping get the original damper as well, even though the tapered head bearings will solidify the front enuf to not need it. I just dig old
Tech
 
I'm going to say yes but I'm only guessing here. I never fooled with any of the early forks. If I recall, on my later forks, the oil level was about 9" down from the top with the stock amount. Adding an ounce more brought it up to about 7" from the top and that seems to work well. As I mentioned above, do some measuring with the stock amount to see where you're at. At the very most, I wouldn't advice getting it any closer than 5" from the top.

Years ago, I was trying to stiffen the forks up on a bike with a sidecar. I used thicker oil and lots more of it than the spec. Turned out to be too much. A couple big bumps popped a seal right out of the fork leg, lol. Boy, did that make a mess. We learn from experience though, huh? That was a lesson I've never forgotten, lol.
 
Nearly died from fork shake on a 1B back in the day. So far my 73 hasn't shown the slightest need for the damper after seals oil and steering bearings. Will have a drummy on the road next summer.
A quick 2 cents is that perhaps old rubber tread patterns contributed to fork shake. Some sort of a harmonic feedback loop? There's an old film of some brits showing nasty fork weave on several brands of bikes of this vintage.


My usual heads up; if you do experience fork weave, push forward on the bars with both arms to damp it out. Pulling back on the bars will worsen it. For some fun, and explanation, google PIO (pilot induced oscillation).
I'll get to some early fork work this winter, will post up what I find.
 
The book calls for 223cc (7.5 oz) fork oil.
I've been running 250cc.
At 30cc per ounce, that's almost an ounce over.

The book also calls for 0.008" clearance of fork leg and top slider bushing.
The clearance limit is 0.020".
Something to check...
 
I"m running Dunlop gold seal k70, a few years old, and had it up to 60mph. a good solid tire. looks og too.:thumbsup:
 
They do look the part on these 1b's
I'll be ordering fork seals and some other stuff for a different bike next week, then start tearing down the front of the 71
 
so I got new clips and washers from dogbunny, thank you. the all balls bearing kit, now waiting on seals.
question-- on 1971 forks, the chrome top on the lower, does that just pull off? ive tried (could try harder?). Looking at slide scrapers on line for 71's, looks like they do.
Do you think I should order new scrapers? This front end has never been apart
 

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